KR20110059954A - Bio-implantable devices and surface reforming method thereof - Google Patents

Abstract

PURPOSE: A bio-implantable device and a surface treatment method thereof are provided to enhance coupling power of bone and an implant by forming grooves on the surface of the implant. CONSTITUTION: A surface treatment method of a bio-implantable device comprises: a step forming grooves having the diameter of 10-50 micrometers on the surface of the bio-implantable device; and a step of forming a titanium dioxide nanoporous layer inside the groove. The formation of the groove is performed in a method of removing coated materials with an etching solution after spraying and coating biocompatible materials of a powdered state on the surface of the groove through a low temperature atomizing method. The nanoporous layer is formed through an anodizing method.

Description

Bio-implantable Devices and Surface Reforming Method

The present invention relates to a surface treatment method of a bio-transplantable body, and more specifically, to form a large crater-shaped groove on the surface of the implant to be implanted in the bone of the human body, and then using the anodic oxidation method The present invention relates to a surface treatment method of a body implantable into a living body which can prevent the nanopore layer from falling off during implant implantation by forming a nanopore layer therein.

In general, dental implants are used to permanently implant teeth and serve to connect human jawbone with artificial teeth. When implanted in the jaw bone, osteoblasts derived from the surrounding bone tissue are bone conduction and osteoinductive healing processes, and new bone tissue is formed and adhered to the surface of the implant. It can play the same role as real teeth. Therefore, the implant should be made of materials that are very friendly to human tissues and should be free of side effects and other chemical and biochemical reactivity.

As a dental implant material, various metals and alloys have been developed so far, mainly using a titanium alloy. However, since such metal materials alone cannot satisfy biocompatibility, chemical stability, etc., a technique of modifying an alloy surface with titanium dioxide or coating a composite material such as calcium phosphate-based ceramics exhibiting biocompatibility or bioactivity It is developed and used.

Meanwhile, in order to strongly bond the implant embedded in the human body with the jawbone, the larger the contact area between the implant and the bone tissue is, the more the method of increasing the roughness of the implant surface has received a lot of attention. There are sand blasting, shot blasting, acid treatment, and the like, and the anodizing method has been developed and applied as a method of imparting micro-roughness.

In Korean Unexamined Patent Publication No. 2008-0111243, in order to increase the contact area with the bone, the surface of the implant is blasted to give surface roughness of about 0.5 to 3 μm in advance and then subjected to anodization to perform nanopores on the surface of the implant. Techniques for forming a layer are disclosed.

However, when nano pores are formed on the surface with a roughness of several micrometers or less by anodic oxidation method, since the nanopores are formed after the titanium implant surface is oxidized to titanium dioxide, the weakness between the titanium inside and the titanium dioxide layer on the surface is weak. Due to adhesion, there is a problem in that the titanium dioxide nano pore layer is easily broken or dropped during implant implantation.

In addition, Korean Patent Registration No. 10-0736826 discloses a technique of forming a nano-pore layer on the implant surface by coating the implant surface with a plasma spray coating of titanium balls, ceramic balls, or calcium triphosphate and then performing anodization. It is.

However, as shown in Figure 1a, in the case of coating a metal material (2), such as titanium balls on the surface of the implant (1) is formed by protruding embossed from the surface of the implant as a friction surface that is in contact with the bone tissue The degree of exposure of the nano pores 4 is intensified, resulting in the dropout of the titanium dioxide nano pore layer during implant implantation.

In addition, as shown in FIG. 1B, when the surface of the implant 1 is coated with a non-metallic biocompatible material 3 such as calcium triphosphate, nanopores 4 may be formed on the surface of the non-metallic biocompatible material. The problem is that nanopores can only be formed in the local area of the uncoated implant surface to increase the contact area with bone tissue. In FIG. 1A and FIG. 1B, reference numeral 5 is an oxide layer.

In particular, various researches and developments have been made to rapidly differentiate adult undifferentiated cells to differentiate into bone cells in order to reduce bone healing period after implantation, among which recombinant bone promoting protein plays a big role in promoting bone formation. It is already known. Therefore, researches on placing bone formation promoters on the implant surface have been conducted, and a technique for forming a nanopore layer on the implant surface of titanium-based implants and supporting bone formation promoters in the pores by anodization is mainly used. However, as described above, when the nanopore layer is destroyed or dropped during implant implantation, the bone formation promoting factor contained in the pore is easily eliminated.

In this context, the present inventors have conducted a study on the surface treatment technology of a new implant to prevent the titanium dioxide nano-pore layer from falling off and shorten the healing period of the bone, forming grooves of at least 10 micro size on the implant surface. The present invention was completed by discovering that the formation of the titanium dioxide nanoporous layer in the groove improves the bonding force between the bone and the implant, and prevents the nanopore layer from falling off or destroying during implant implantation. .

Therefore, an object of the present invention is to form a groove of at least 10 micro size on the implant surface to increase the bonding force between the bone and the implant, and at the same time to form a titanium dioxide nano-pore layer in the groove to drop the nano-pore layer during implant implantation It is to provide a surface treatment method of the implant that can prevent.

In order to achieve the above object, in the present invention, forming a groove having a diameter of 10 to 50 microns on the surface of the body implantable in the living body, and forming a titanium dioxide nano-porous layer in the groove Provided is a method for treating a surface of a body implantable into a living body.

In another aspect, the present invention provides a body implantable body, grooves formed to have a diameter of 10 to 50 micrometers on the surface of the body; And it provides a body implantable to the living body, characterized in that it comprises a nano-pore layer formed in the groove.

In the present invention, the step of forming the groove is preferably carried out by spray coating the biocompatible material in powder form on the surface through a low temperature spraying method, and then removing all of the coated material with an etching solution.

The nanoporous layer inside the groove is preferably formed by anodization. The anodic oxidation method is generally well known, such as disclosed in detail in the above-mentioned prior art, and thus a detailed description thereof will be omitted.

The biocompatible material preferably contains at least one selected from a calcium phosphate compound and a biofree compound as a biocompatible powder or bioactive powder. The calcium phosphate compound is preferably at least one selected from apatite, calcium triphosphate (TCP), calcium phosphate (TTCP), calcium diphosphate and calcium monophosphate. The bioglass compound is preferably bioglass or biocrystallized glass containing CaO, SiO ₂ and P ₂ O ₅ as components.

The powder particle size of the biocompatible material is preferably in the range of 0.01-200 μm.

The etching solution is at least one selected from phosphoric acid, hydrochloric acid, nitric acid, hydrofluoric acid, and sulfuric acid.

The implantable body in the present invention may be a medical implant, including a dental implant such as an artificial tooth, or an orthopedic implant such as a spinal fixation system, a typical dental implant. The material of such a bio-transplantable body is titanium metal or an alloy thereof which is hardly reactive with a variant.

In the present invention, if the diameter of the groove exceeds 50 microns, the support area of the surface of the implant screw may be too small to withstand the load during implant implantation, whereas if the diameter of the groove is less than 10 micro, the size of the groove is too large. It is difficult to anticipate the effect of preventing nanopores from falling off during implant implantation because the nanopores formed inside are likely to be exposed to the implant surface.

In addition, in general, a sustained release technology in which a growth factor is slowly released by coating a growth factor material on a polymer such as collagen or hydrogel is applied. In the coating of the polymer inside the recess of the implant, the polymer material is used. Since the size of is at least 10 micro or more, when the groove is less than 10 micro, the polymer is exposed to the friction surface, which is not preferable.

According to the present invention as described above, by forming a groove size of 10 to 50 microns on the surface of the implant and then forming a titanium dioxide nanopore layer inside the groove to increase the binding force between the bone and the implant, at the same time nano pores at implant implantation There is an advantage that can prevent the layer from falling off.

Hereinafter, the present invention will be described in detail.

Cold coating process is a new coating technology that accelerates the compressed gas (He, N ₂ , air, or a mixture of these gases) into a supersonic jet and sprays the powder onto the subject to form a coating layer on the subject. to be.

This low temperature spray coating method can maintain the intrinsic properties of the initial particles by using powders that have already been crystallized or have unique characteristics as initial particles, and can minimize the preheating of the subject because the coating method is based on the kinetic energy of the powder. There is an advantage that low temperature process is possible and high productivity can be expected. In addition, depending on the powder material and the spraying speed, the powder can be driven deep into the surface of the subject. When the sand blasting or the short blasting method is used without using such a low temperature spraying method, the momentum of the powder sprayed on the subject is not sufficient, and it is difficult for the powder to form micro grooves in the subject.

In the present invention, by using such a low-temperature spray coating technology, biocompatible powder is coated on a biological metal material, and the powder is melted through an acid treatment to form micro-sized grooves, and the grooves are anodized inside the grooves. A method of forming a titanium nanoporous layer is provided.

Figure 2 schematically shows an example of a low temperature spray coating apparatus used in the present invention. The cold spray coating of the present invention can be carried out by the cold spray coater shown in FIG.

Such a low temperature spray coating machine includes a gas tank, a controller, a gas heater, a powder feeding device, a powder heater, and a nozzle. The gas supplied from the gas tank is sent to the gas heater and the powder feeder through the controller, and the gas heater heats the gas to increase the pressure to induce the gas to rise, and the powder feeder supplies powder to the gas sent from the controller. The powder heater heats the powder. At the nozzle, a mixture of hot gas and gas powder meets and injects a high velocity gas-powder jet.

The powder in the jetted jets has a high kinetic energy and collides with the surface of the subject (substrate) to combine with the subject to form a coating layer. The subject then moves and cools down simultaneously with the coating.

The present invention provides a process for etching a powder coated by a low-temperature spraying method to form a groove in a subject, which may cause side effects after implantation in a living body if the coated powder remains unetched even in a small amount in the etching process. As such, the powder to be coated is preferably a powder of a biocompatible material. As the biocompatible material powder, for example, a calcium phosphate compound such as apatite hydroxide (HA), or a biofree compound such as bioglass or biocrystallized glass mainly composed of CaO, SiO ₂ , P ₂ O ₅ , or a mixture thereof Can be used.

Since the size of the biocompatible material powder coated on the subject directly affects the impact amount, it is an important factor that greatly influences the formation of the groove. If the powder size is too small, the mass of the powder is reduced, resulting in a decrease in kinetic energy, and thus, it becomes impossible to be embedded in the subject deeply or to form grooves of a desired size. In addition, if the powder is too large, it is not accelerated by gas enough, so the kinetic energy of the powder is reduced, so that the powder cannot be deeply embedded. For this reason, 0.01-200 micrometers is suitable for the size (diameter) of the powder used by this invention, Preferably it is 10-200 micrometers.

At this time, the powder of less than 1㎛ may not be accelerated enough to adhere to the subject during low-temperature spraying due to the small size does not have sufficient kinetic energy, in this case 1 ~ to coat such a small size powder with a low temperature spray coating It may be sprayed by granulation to a size of 10 μm. In this way, sufficient kinetic energy can be imparted to the grains, so that grooves having a desired size can be formed in the subject.

In order to form grooves on the surface of the subject by etching the biocompatible powder layer coated by the low temperature spraying method, the present invention provides a method of completely dissolving the biocompatible powder by immersing the surface of the formed coating layer in an acid solution. . The acidic solution is an aqueous solution of phosphoric acid (H ₃ PO ₄ ), hydrochloric acid (HCl), nitric acid (HNO ₃ ), hydrofluoric acid (HF), sulfuric acid (H ₂ SO ₄ ) and the like. It is preferable in terms of. In order to dissolve the biocompatible powder, a method of immersing in the acidic solution and applying heat or ultrasonic wave may be used.

In order to provide nano-sized pores on the groove surface formed by dissolving all of the biocompatible powder coated on the surface of the body implantable to the living body, the present invention provides a method for anodizing the body implantable into the living body.

When the nano-sized pore layer is formed after the grooves are formed in this way, as shown in FIG. 3, since the nano-sized pore layer 2 is formed inside the grooves 1 and is not exposed to the outside, bone tissue is implanted during implantation. The area that is directly rubbed with is reduced, significantly reducing the possibility of the nano-sized pore layer falling off. In FIG. 3, 3 is an oxide film layer.

In order to perform the anodic oxidation, the material of the body implantable into the living body should be a metal, preferably a titanium metal or a titanium alloy. Anodization is performed by immersing an object having the grooves formed in an acid solution with an opposite electrode and applying a voltage to react oxygen ions contained in the electrolyte with the surface of the substrate to form an oxide layer, which is then etched and formed. By repeating to form the nano pores.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the scope of the present invention is not limited to the following examples.

(Example)

Titanium metal implant fixture was used as a subject for low temperature spraying. At this time, the low temperature spray coating equipment was used as shown in Figure 2, the air was used as a carrier gas. The temperature of the gas is 600 ℃, the subject temperature is 100 ℃, the temperature of the powder at room temperature, the pressure of the injected gas is 25kg / cm ² , the distance between the injection nozzle and the subject is 1.5cm, the injection flow rate is 0.2g / sec It controlled, and sprayed for 1 minute with the subject fixed.

At this time, the coating material was a hydroxide active apatite powder which is a bioactive material, in order to sufficiently increase the impact amount, it was used agglomerates of several tens of ㎛ size as shown in FIG. Apatite hydroxide powder aggregates were synthesized by spray drying and sintering apatite hydroxide nanoparticles.

FIG. 5 is a scanning electron microscope (x1000 SEM) photograph of the surface of an implant fixture coated with hydroxide apatite powder. FIG. Referring to FIG. 5, which is enlarged 1000 times, it can be seen that the coating of a titanium oxide implant, which is a subject, is embedded in the form of a deeply embedded hydroxide of apatite.

Chemical etching was used to remove the hydroxide apatite coated on the implant surface. The implant was immersed in an aqueous solution of pH 2 maintained at 50 ° C. and sonicated for 10 minutes.

6 is a scanning electron microscope (x500 SEM) photograph after dissolving all of the hydroxide apatite powder by immersing the subject in an aqueous phosphoric acid solution after coating the hydroxide apatite powder according to the present embodiment. Referring to FIG. 6, which is enlarged 500 times, it can be confirmed that the crater-shaped groove having an average size of 20 μm is sufficiently formed. In addition, it can also be seen that the hydroxide apatite powder is in an etched state.

In order to form a nano-pore layer in the groove formed in this way, a titanium dioxide nanotube was formed on the implant surface through anodization. In the anodic oxidation, a solution in which 1 wt% of water and 0.5 wt% of NH ₄ F was added to ethylene glycol was used as an electrolyte. An anode and a platinum plate were immersed in a cathode, and a voltage of 50 V was applied to the grooved implant. It was made by applying for 1 hour.

FIG. 7 is a photograph of the surface of the implant subjected to anodization after forming the recess according to the present embodiment with a scanning electron microscope (x50,000 SEM). Scanning electron micrographs magnified 50,000 times show that the pores of about 100 nm size are uniformly and regularly formed on the implant surface.

As described above, according to the present invention, a groove having a size of 10 to 50 μm may be formed in an implant made of titanium metal, and nano-sized pores may be formed in the groove, and a growth promoting factor may be formed in the nano-sized pores formed in the groove. By supporting the implant can be implanted in the bone without falling off the growth promoter or nano-sized pore layer.

Figure 1a is a schematic diagram showing a state in which the embossed coating on the surface of the implant using a ball of a metal material according to a conventional method,

Figure 1b is a schematic diagram showing a state of embossed coating on the surface of the implant with a non-metal ceramic according to a conventional method,

Figure 2 is a schematic diagram showing an example of a low temperature spray coating apparatus used in the present invention,

3 is a schematic diagram showing a state in which nanopores are formed on the surface of the implant formed grooves by anodization according to an embodiment of the present invention,

Figure 4 is a scanning electron micrograph showing the apatite hydroxide powder particles used in low temperature spray coating according to the present invention,

5 is a scanning electron microscope (Scanning electron microscope, x1000 SEM) photograph of the surface of the implant fixture coated with apatite hydroxide powder according to an embodiment of the present invention,

6 is a scanning electron microscope (x500 SEM) photograph after dissolving all of the hydroxide apatite powder after coating the apatite hydroxide powder in accordance with an embodiment of the present invention;

7 is a photograph of the surface of the implant after anodization after forming a groove according to an embodiment of the present invention by a scanning electron microscope (x50,000 SEM).

Claims (12)

Forming a groove having a diameter of 10 to 50 microns on the surface of the body implantable into the living body; And And forming a titanium dioxide nano-pore layer in the groove. The method of claim 1, The step of forming the groove is a surface treatment method characterized in that the spray coating the biocompatible material in the form of powder on the surface through a low temperature spraying method, and then removing all of the coated material with an etching solution . The method of claim 1, The nano-pore layer inside the groove is formed by the anodization method. The method according to claim 1 or 2, The biocompatible material is a surface treatment method comprising at least one selected from a calcium phosphate compound and a bio-free compound as a biocompatible powder or a bioactive powder. The method of claim 4, wherein The calcium phosphate compound is at least one selected from apatite, calcium triphosphate (TCP), calcium phosphate (TTCP), calcium diphosphate and calcium monophosphate. The method of claim 4, wherein The bio-glass compound is a surface treatment method characterized in that the bio- or bio-crystallized glass containing CaO, SiO ₂ and P ₂ O ₅ as a component. 3. The method of claim 2, Powder particle size of the biocompatible material is a surface treatment method characterized in that the range of 0.01 ~ 200㎛. 3. The method of claim 2, The etching solution is a surface treatment method characterized in that at least one selected from phosphoric acid, hydrochloric acid, nitric acid, hydrofluoric acid and sulfuric acid. The method of claim 1, The material of the body implantable in the living body is a surface treatment method characterized in that the titanium metal or titanium alloy. The method of claim 1, The biotransplantable body is a surface treatment method, characterized in that the medical implant. As a biotransplantable body, Grooves formed to have a diameter of 10 to 50 micrometers on the surface of the body; And A bio-transplantable body comprising a nano-pore layer formed inside the groove. The method of claim 11, The bio-implantable body is a bio-implantable body, characterized in that the medical implant.

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